Open water vessels have existed for centuries. For just as long men working the vessels have fallen overboard, necessitating the need for open water rescue. Historically the survival rate was very low due to the nature of the craft, the speed with which they could respond, the lack of ability to survive adverse conditions, the techniques available to the rescuers.
Modernly, the speed of the vessels involved, the maneuverability, the rescue techniques and related rescue equipment have improved greatly. Even modern sailing craft are able to return to the area where the person went overboard in a reasonably short time, due in great part to auxiliary power. However, it must be noted that stopping a vessel of any type next to a person who has fallen overboard, regardless of whether or not they are conscious, is very difficult in adverse conditions such as high winds, high waves and/or strong currents.
Also to be considered, the equipment and methods in use today are far superior to those employed in the past. Regulatory agencies such as the U.S. Coast Guard set safety requirements and have the power to monitor all craft, levying fines and/or restricting operation when required. The combination of these changes and efforts have improved the survivability of a person who inadvertently falls overboard.
Contemporarily, several methods for recovering a person who has fallen overboard, referred to as ‘man overboard’, or MoB, are known and in use. These run the gamut from throwing a simple life ring or life jacket to complex harness-and-sling equipment. Each of these devices has had some success, but each has a number of serious drawbacks. By way of example, a life ring requires that the man overboard be conscious and capable of assisting his/her own rescue by grasping the device. And while rare, throwing a life ring at a man overboard may cause injury if the device strikes the individual on the head.
Sling and/or harness devices require skill to use, usually requiring third party assistance, for example helicopter crews, and can require significant training to be effective. As with the simple life ring method, if the individual is unconscious these devices are even less useful. And unlike the simple ring or horseshoe devices, the sling/harness devices are expensive.
Each of the contemporary devices may also be used with a series of vessel maneuvers that allow the retrieval of the man overboard. The most successful maneuver can be described as a buttonhook because the vessel turns immediately after deploying the retrieval device, moves away from the MoB far enough to allow the device tether to deploy. Once deployed, the vessel then performs another tight turn, passing between the Mob and the device to ensure that the tether does not foul in the vessel's prop or hull. Once past the Mob, the vessel turns a third time, causing the tether to drag in close proximity to the Mob.
While this method works well enough for a conscious MoB, it fails regularly for an unconscious MoB. This is because the unconscious MoB is not able to react to the presence of the tether, rendering him/her unable to grasp the rescue device. Moreover, if the MoB is slightly submerged, due for example to heavy clothing, the tether will simply pass over the intended rescue target requiring, at a minimum, a second, time consuming set of maneuvers. What would be desirable would be an apparatus and method that would allow an MoB to be recovered reliably whether or not the MoB is able to assist in his/her own rescue and whether or not the MoB is slightly submerged.